Steam-generating system



L. L. SCOTT.

STEAM GENERATING SYSTEM.

APPLICATION FILED FEB. 8,1918.

Patented July 26, 1921.

IIIIIIIIIII UNITED STATES PATENT OFFICE.

LEWIS L. SCOTT, OF ST. LOUIS, MISSOURI, ASSIGNOR TO STANDARD ENGINEERINGCOMPANY, OF ST. LOUIS, MISSOURI, A GQRPORATION.

STEAM-GENERATING I SYSTEM.

T 0 all whom it may concern Be it known that I, LEWIS L. Soo'r'r, acitizen of the United States, residing in the city of St. Louis,Missouri, have invented a newand useful Improvement in Steam-GencratingSystems, of which the following is a specification.

This invention is constructed with especial reference to its use uponsteam driven automobiles, by means of which to automatically so controlthe delivery of fuel to the combustionchamber, and water to thegenerator, that steam shall be generated in said generator in the volumenecessary to meet the varying demands therefor, and shall be maintainedin substantially uniform condition as to pressure and temperature. Thespecific embodiment. of the invention shown is contrived with specialreference to its use in connection with a steam generator of thesemi-flash type.

Regulators for use in semi-flash boilers have heretofore been devisedwhich, theoretically, should give perfect results; but in actualpractice they do not, because of their sluggish action and because ofthe time required to realize theQefl'ects caused by the action of saidregulators. Overheating of the generator or flooding same with water isthe usual result, unless the regulators are assisted manually by askilled operaton.

One object of my invention is to provide a steam generatin system thatcan be put into operation by -t e closing of an electric switch, and toprovide automatic devices for such system which will keep the steam at aconstant pressure and temperature regardless of the sudden changes indemand for steam. A further object is to make said devices instantaneousin their action, so that when there is a sudden call for a large amountof steam there will be no material drop in the steam pressure. A furtherobject is to provide safet devices for the steam generatln system w ichwill automatically shut 0 the fire, if the water tank is empty, or willshut off the water from the generator if thefuel tank is empty, andfurther to provide a system in which heavy hydro-carbon fuel can beignited at normal temperature by electric ignition means, and soarranged that if the electric device fails, unburned fuel cannot beforcedinto the combustion chamber and water cannot be forced to thegenerator coils. In

Specification of Letters Patent. Patented July 26, 1921. Applicationfiled February 8, 1918.

Serial No. 216,024.

other words, it is a system that can be used by the average unskilleddriver of an automobile, without fear of damage to any part of saidsystem, and without fear of danger to the operator of said automobile.

In the accompanying drawings, Figure 1 is a diagram of parts andconnections illustrating one embodiment of my invention,

Fig. 2 is an end View of a sparking device used for igniting the fuelmixture in the combustion system,

Fig. 3 is a side view of one of the elements of said sparking device.

Referring to the drawings, 1 represents the steam generating coils of asemi-flash boiler such as shown in Patent No. 659,837 to R. H. White. 2-is a continuous tube preheating coil which is connected to the steamgenerator coils through the check valve 3,. said check valve allowingwater to pass from the. preheating coil to the generating coils. 4c is asteam storage coil, one end of which is connected to the steam outletpipe 5 through the blow off valve 6 (said blow off valve being set toallow steam to pass from the generating coils 1 to the steam storagecoil 4, when the pressure in said generator coils 1 has reached apredetermined amount andwhen steam is being generated in coils 1 inexcess of the demand therefor) and the other end of the steam storagecoil 4 is connected to the steam generating coils 1 through the checkvalve 7 at any convenient point such as shown at 8. It will be notedthat at no time will the steam storage coil rob the generator coils 1 ofsteam, or in any way interfere with the regular generating of steam insaid generating coils 1. The purpose of said steam storage coil is tofill in the gap of the few seconds required for the fire to becomeeffective (once said fire has been automatically shut off and therecomes a sudden demand for steam) by returning the steam stored in saidstorage coil to the generator coils 1, when the pressure in saidgenerator coils drops below the pressure in the steam storage coil. Thisaction is entirely automatic.

The pipe 9is connected to the steam stor age coil and runs to theBourdon tube 10. Said Bourdon tube 10 acts, at a predeter-- minedpressure in the steam storage coil, to open an electric switch. Thepurpose of such action will be described later.

The steam generator coils, steam storage coils and the preheating coilsare all inclosed by a suitable refractory heat insulating material, thesteam generator coils being separated from the steam storage andpreheating coils by the partition 11 which forms two compartments; saidpartition being made of refractory material and terminating short of thetop of the casing inclosing the coils and providing communicationbetween the two compartments for the products of combustion which passout of the casing at the lower part of the compartment containing thepreheating and steam storage coils.

The steam outlet pipe 5 connects, through a suitable throttle valve 12,to the steam engine 13. The exhaust pipe 14 of said engine is preferablyrun through the water tank 15 (for the purpose of cooling the exhauststeam and heating the water in said tank) to a suitable steam condenser,not shown. i

For supplying water to the steam generator I use two plunger water pumps16 and 17. While both of these pumps may be driven from the steamengine, I prefer in some cases, to drive the pump 16 from the steamengine and the pump 17 by an electric motor 18.- The numeral 19indicates a worm, on the electric motor shaft 19*, which drives the wormwheel 20; said worm wheel carrying the crank pin 21 which connects tothe piston of the pump 17, through the rod 22. The pump 17 is providedwith the usual check valves 23 and the pump 16 is likewise provided withthe check valves 24. The intake pipe 25, to the pumps, connects with thelower part of the water tank 15. The discharge pipe 26, from the pumps,connects to the lower end of the preheating coil 2.

An air compressor 27 is preferably driven from the steam engine 13(although it may be driven by an electric motor) and furnishes air athigh pressure to the tank 28; said air tank 28 is provided with a handpump 29. Air from the tank 28 passes through the reducing valve 30,which allows air to flow from the tank at a low and constant pressure,and enters the pipes 31 and 32. The pipe 31 leads to the top of the fueltank 33 and forces the fuel in said tank to the float valve 34. The pipe32 leads to the air nozzle 35, which-nozzle serves the purpose ofatomizing fuel from the fuel nozzle 36, said fuel nozzle being connectedto the float valve 34. While I have shown but one air and one fuelnozzle, any number of these nozzles may be used as desired. The atomizedfuel is ignited by the spark plug 37 sald spark plug being connected tothe hlgh tension winding 38 of a vibrating spark coil.

As before stated, I prefer to use a heavy hydro arb n q uel, such askerosene,

which is atomized as before described, and

ignited at normal temperature by the electric spark. I have found thatthere are certain conditions which regulate the initiation of combustion(by an electric spark) of a mixture of air and atomized kerosene, z'.6., the ratio of the air to the fuel, size of particles of fuel,velocity at which particles of fuel travel, and the quantity of heatgenerated by the electric spark. Liquid kerosene cannot be finelydivided by atomizing same with a low pressure blower. There must be apressure of at least two lbs., in order to finely divide said fuel. Ifthe fuel is finely divided, and the common spark plug (such as used ongasolene engines) is used for igniting same, I have found that themixture of air and fuel must be rich in hydro-carbon or ignition willnot take place. In order to make a completely combustible mixture, anadditional supply of air must be added. Any suitable means may beemployed to supply this additional air; in the drawing I show a blower39 which is driven by the electric motor 18. The resultant mixture isdirected to the combustion chamber 40 through the tube 41. I have foundthat a completely combustible mixture of air and finely divided kerosenecan be ignited by a series of electric sparks, such as shown in thesparking device in Figs. 2 and 3,in which 42 is a porcelain insulatorcontaining a series of spark points 43. A number of spark tubes 42 (seeFig. 2) are required if the velocity of the mixture is high. Said tubesmay be joined by the insulator ring 44..

The controls for the fuel mixture of the burner, the water to the steamgenerator and current to the spark plug will next be described.

The numeral 45 indicates a storage battery which may be charged by asuitable dynamo, not shown. 46 is a manually operated switch connectingthrough the wire 46 with the positive side of the battery. The wire 47is connected to an insulating screw 48. A spring held lever 49 isarranged to normally make contact with the screw 48; sald lever 49 isarranged in cooperative relation with the free end of the Bourdon tube10, the relation between the Bourdon tube 10 and the lever 49 being suchthat when the pressure of steam to which the Bourdon tube issubjectedreaches a predetermined amount, the lever 49 will move awayfrom the screw 48 and break the electric circuit between said screw 48and lever 49. The wire 50 is connectedto the lever 49 and leads to apoint 51, 'at which point the circuit divides. A wire 52 connects withthe wire 50 at the point 51 and runs to the primary winding 53 of avibrating spark coil. e

A solenoid 54 is connected in series with the wire 55 leading to thespark plug 37. he numeral 56 indicates a stationary insu- The core 58 ofthesolenoid 54 makes contact with the part 56 and is connected to themo- 1 tor 18 by the wire 59. When the normal amount of current isflowing tothe spark plug 37, the spring 60 on solenoid 54: maintams. thecore 58 in ehgagement with the contact 56 and preventsthe opening of thecircuit to the motor 18, but it an abnormal amount of current is passingthrough the solenoid 54: (due to a'short circuit in the Y spark plug37), the solenoid acts to open the circuit to the motor 18. lln thisoperation the core 58 is drawn downward against the resistance of thespring 66 to separate it from engagement with the contact 56 whereby thecircuit to the motor is broken over the wire 59. Under these conditionsthe motor 18 (and all electrical equipment connected in series.therewith) cannot operate until the spark plug 37 is restoredto normalworking condition.

The wire 61 leads from the motor 18 to a solenoid 62. Une end of thecore of said solenoid 62 is connected to a brass stem 62 (nonmagnetic),of the valve 63' in the air line 32. lhe other end of the core oi thesolenoid 62 is connected to a piston 6t, which :operates in the cylinder65 ;.said cylinder 65 has a small opening 66 at its lower end whichconnects to the atmosphere. The "wire 67 from one side or the primarycoil 53 is connected to the cylinder 65. The wire 68 is connected to thenegative side of the battery 45 and runs to the insulated contact 69.The core of the solenoid 62 carries the sliding contact 70 whichoperates to open and close the circuit to the primary coil 53.

When the sliding contact 70 is in engagement with the insulated contact69, current will flow through the cod 53 over wires 47, 50, 52, 67 and68. When current passes through the solenoid 62 the stem 62 will bedrawn to the right against the resistance of the spring 71 and thevalvein the air line 32 will be opened, allowing air to pass to thenozzle 35 whereby said. air will draw fuel from the nozzle 36 andatomize same; said mixture, which is rich in hydro-carbon, is ignited bythe spark plug 37 and additional air to form a completely combustiblemixture is supplied from the motor-driven blower 39. The movement of thepiston 64. is timed by the size or the opening 66 in the .cylinder 65 inorder to control the rate of movement of the contact 7 0 over thecontact 69, andburrent to the primary spark coil 53 is cut oil whencontact 70, moves or of said contact 69 after a predetermined period oftime. The spring-71 returns the core or the solenoid 62 to normalposition when the current is not running through the solenoid. The wire72connects the solenoid 62 to the contact 73- The numeral 7% indicates adiaphragm which is pressed into contact with. the insulated point 75, bythe weight of the 7 fuel in tank 33 on said diaphragm. If the fuel tankis empty the diaphragm 74 acts to break the circuit between the screw 73and the point 75. This operates to cut out the motor 18 by breaking thecircuit thereto over the wire 72. -The wire 76 connects to the point andruns to the screw 77 on the water tank. 78 is a diaphragm which ispressed into contact with the insulated point 9 by'the weight of thewater in tank 15. If the water tank is empty, the diaphragm 78 acts tobreak the circuit between the screw 77 and the point 79. This alsooperates to cut out the motor by breaking the circuit thereto over thewires 7 6 and 72. The wire 80 leads from the point 79 to the negativeside of the battery 45, which completes the circuit.

The water pump 17 is driven by the motor 18, and the blower 39 is alsodriven by said motor 18. As air to the nozzle 35 is always furnished ata constant lined pressure (by virtue of the reducing valve 30) and iscontrolled by the solenoid 62v which is connected in series with themotor 18, it will be seen that the fuel to the combustion chamber andwater to the generator, from pump 17, will the burner, and water to thegenerator, supplied by the action of the pump 17, will .be turned on orcut 06 according to the demand for steam as governed by road conditions.Such instantaneous control or the spark-plug, burner, and pump iseifected though the action of the Bourdon tube 10,

which operates, according to the pressure of steam in the generator,tomake or break the contact between the lever 4:9 and screw 48, andthereby close or open, respectively, the circuit to the motor 18, whichgoverns the operation of said spark plug, burner, and pump.

When lever 19 is in contact with screw 48, the circuit to the motor isclosed from battery {15 through switch 46, wire 47, screw 48, arm 4:9,wire 50, wire 57, contacts 56 and 58, wire 59 and wires 61, 72, 76 and80. When the arm 49 is moved out of contact lid with screw 48, it isobvious that the connec- 7 tion between wires 47 and 50 will be brokencontact 70 into engagement with the stationarycontact 69 thereby placingthe primary spark coil 53 in the circuit ofthe battery as heretoforedescribed. Current to the spark plug 37 then passes from the secondarycoil 38 over the wire through solenoid 54 to the spark lug, the returnbeing through ground. hen the contacts &9 and 48 are separated, or whenthe sliding contact 70 passes off of the fixed contact 69, no currentcan pass to the coil 53 and hence the spark plug will be cut out.

The pump 17 is operated direct from the motor 18 by means of the shaft19 and worm 19, as heretofore described. When the arm 49 breaks contactwith screw 48, cutting out the motor 18, it necessarily follows that thepump 17 will cease to operate and the supply of water to the generatorwill be discontinued.

Finally, when the circuit to the motor is broken by the movement of thearm 49 out of engagement with the screw 48, the solenoid 62 will bedeenergized, the valve 63 closed to prevent air passage through the pipe32 to the nozzle 35 and hence the burner will cease to function as thesupply of fuel to the burner is dependent upon the blast'of air from thenozzle 35.

As it is desirable to change the ratio between the water supplied bypump 17 and the fuel to the combustion chamber, (under different loadconditions) I provide the water pump 16 as before described. I will nowdescribe the control of the water from pump 16 to the generator coils.

I prefer to use a vapor tension thermostat 81 which is connected to thesteam generator coils 1, in the liquid heating portlon of said coils.The thermostat is subjected to temperature chan s of the fluid in thegenerator coils 1. he pipe 82 connects the thermostat 81 to the Bourdontube '83. When a predetermined pressureis created in said Bourdon tube83 (by reason of the high temperature in the portion of the generatorwhere the thermostat 81 .is located),'said tube will move. the springheld lever 84 into contact with the insulated screw 85, to close anelectric circuit. This circuit comprises a wire 86 connected to the arm84 and leading to a solenoid 87, a return wire 86' leading from thesolenoid 87 and connected to the wire 80 which pames to the negativeside of the battery 45, wire 47 and a branch wire 47 connecting wire 47with the contact screw 85. The core ofthe solenoid 87 is connected to avalve stem 87 which controls a valve-88 in the suction line of the pump16. A spring 89 operates normally to raise the core of the solenoid 87and close the valve 88.

When contact is made between arm 84 and screw 85, due to increasedtemperature, the solenoid 87 will be energized and operate to draw.downward stem 87 against the resistance of spring 85 and open the valve88 in .the suction line of pump 16 so that addi tional water will bepumped to the generator until such time as the thermostat cools down andthe pressure drops in the Bourdon tube 83, which latter then moves tobreak contact between arm 84 and screw 85 and thereby break the electriccircuit to solenoid 87, whereupon the valve 88 in the suction.

line of the pump 16 will be closed automatically by action of the spring89.

It Wlll be seen from the foregoing that I have rovided a steamgenerating system, where y the fuel to'the combustion chamber and thewater to the generator are supplied in substantial unisdn and indefinite relations, and thatsaid supplies are controlled instantlyaccordin to changes in the demand for steam. have also provided anadditional Water supply which operates independently of the firstmentioned water supply, whereby the ratio between fuel and water can bechanged automatically, depending on the temperature at a fixed point inthe steam generator coils. I have provided an electric system whichmakes the above mentioned operation instantaneous, and whereby there isa certain cooperative relation between the working of each part in thesystem and in which the dan ers of burning the generator, or flooding te generator with water, or flooding the combustion chamber with unburnedfuel, have been eliminated. I have also provided a means whichcooperates with the regulating devices, to store steam during periodsthat the generator is not working to full capacity and to return saidsteam to the generator coils, if there is a slight drop in pressure insaid generating coils, due to small inaccurary in said re ulatingdevices.

I have described the best embodiment of my invention now known to me;but it is to be understood that the apparatus shown is merelyillustrative and that the invention can be carried out by other means.

I claim 1. In an apparatus for generating steam, a steam generator,means for supplying lkpuid to the generator, means for supplying ratusfor automatica ly controlling, elther to turn on or to shut off insubstantial unifuel for heating the generator;

son, said electrical device, the supply of liquid to the generator andthe supply of 3. In an apparatus forgenerating steam, a steam generator,an electncally driven pump for furnishing liquid to the generator, aburner, electrically controlled means for furnishing a fuel mixture tosaid burner, an electrical device for igniting said fuel mixture, anelectrical circuit including the said electrically driven means, thecontrolling means for the fuel mixture and said i niting device, and amake-and-hreak switc in said circuit, whereby on closing said switch thesupply of liquid to the generator, the supply of fuel mixture to theburner and the ignition of said fuel mixture may be occasioned insubstantial unison. I

40 111 an apparatus for generating steam, a

, steam generator, a pump for furnishing liquid to the-generator, aburner, electrically controlled means for furnishing a fuel mixture tosaid burner, an electrical device for igniting said fuel mixture, alolower for supplying air to the ignited mixture, a motor forsimultaneously operating said pump and blower, an electrical circuitincluding the motor, said electrical igniting device and the controllingmeans for the fuel mixture, and a make-and-break switch in said circuit,whereby on closing said switch the functions of liquid supply, fuelsupply, combustion, and air supply may be simultaneously initiated.

5. ln an apparatus for generating steam, a steam generator, means forsupplying liquid to the generator, means for supplying a fuel mixturefor heating the generator, an electrical device for igniting said fuelmixture, and single means for automatically and siinultaneouslycontrolling said electrical device, the supply of liquid to thegenerator and the supply of fuel tor heating the generator.

6. In an apparatus for generating steam, a steam generator, means forsupplying li uid to the generator, means for supplying a tuel mixturefor heating the generator, an electrical device for igniting said fuelmixture, and singleuineans governed loy generator conditions forautomatically controlling'in substantial unison said electrical device,the supply of liquid to the generator and the supply of fuel for heatingthe genorator.

7. Flu an apparatus for generating steam, a stearn generator, means forsupplying lie nid to the generator, means tor supplying a i rel mixturefor heating the generator, an electrical device for igniting said toolmixture, and means for automaticall controlling said electricalidevice,the supp y or liquid to the generator, and the fuel for heating thegenerator, in substantial unison With the rise or fall thepressure ofsteam alcove or below a predetermined degree.

" 8. In an apparatus for generating-steam,a steam generator, anelectrically controlled device for en pl 1i uid to the orator anelectricall y cgl llii olle ddevice fo r s upply ingfuel forheating-thegenerator, anelectrical device for igniting said fuel, and meansgoverned by generator conditions for automatically closing or openingthe elec-' tric circuits to said igniting device, the device forsupplying liquid to the generator and the device for supplying fuel forheating the generator.

9. In an apparatus for generating steam, a steam generator, anelectrically controlled device for supplying liquid to the generator, anelectrically controlled device for supplying fuel for heating thegenerator, an electrical device for igniting said fuel, and means,governed by generator conditions, for automatically and simultaneouslyopening or closing the electric circuit to said igniting device, thedevice controlling the sup ply of liquid to the generator and the devicecontrolling the supply of fuel for heating the generator.

10. In an apparatus for generating steam, a steam generator, means forsupplying liquid to the generator, means for supplying a fuel mixturefor heating the generator, an electrical device for igniting said fuelmixture, means for automatically controlling in substantial unison saidelectrical device, the supply of liquid to the generator and the supplyof fuel for heating the genorator, and independent means forautomatically varying the relation between the supplies of liquid andfuel.

11. in an apparatus for-generating steam, a steam generator, anelectrically controlled device for supplying li uid to the generator, anelectrically controlle device for en gm plying fuel for heating thegenerator, an ectrical device tor igniting said fuel, means governed laygenerator conditions tor automatt .cally controlling the operation orthe three devices named, and independent means, also governed bygenera-tor conditions, for automatically varying the relation betweenthe supplies oi liquid and fuel.

1%. In an apparatus for generating steam, a steam generator, anelectrically controlled device for supplying liquid to the generator, onelectricall controlled device for supplying fuel tor eating thegenerator, an electrical device for igniting said fuel, means governed hvariations in steam pressure for automatica y controllin the operationof the three devices name and independent means, governed loytemperature conditions in the generator, for automatically varying therelation between the supplies of liquid and fuel.

13. In an apparatus for generating steam, a. steam generator, means forsupplying liquid to the generator, means for-supplying fuel for heatinthe generator, an elecmeal-device for igniting the fuel, and autorecmatic means, rendered operative by a short circuit in said ignitingdev1ce,.for shutting off the supply of fuel and liquid in substantialunison.

14. In an apparatus for generating steam, a steam generator, means forsupplying liquid to the generator, a tank for containing the liquid,means for supplying fuel for heating the generator, a cut-off deviceassociated with said liquid tank, and automatic means for shutting offthe fuel rendered operative by said cut-off device when the liquid inthe liquid tank has fallen to a predetermined level.

15. In an apparatus for generating steam, a steam generator, means forsupplying liquid to the generator, means for supplying fuel for heatingthe generator, a tank containing said fuel, a cut-off device associatedwith said fuel tank, and automatic means for shutting oifthe liquid tothe generator rendered operative by said cut-01f device when the fuel inthe fuel tank has fallen to a predetermined level.

16. In an apparatus for generating steam, comprising a steam generator,a combustion chamber arranged in cooperative relation with the same, anda steam engine connected to the steam delivering pipe of said generator,a liquid supply for the generator comprising two water pumps and, theirconnections to a source of liquid, one of said pumps bein driven fromsaid engine, a fuel supply to tl de combustion chamber, an electricdevice for ignitinthe fuel, means for automatically controllmg theliquid supply from one of said pumps, the fuel supply and saidelectrical device in substantial unison and in accordance with generatorconditions, and independent means for automatically controlling thesupply of liquid from the other pum accordingto generator conditions.

17. In an apparatus for generating steam, a steam generator, a fuelsupply for heating the generator, an electrical device for igniting thefuel, a liquid supply for the genera tor comprising two water umps, asteam engine for driving one of said water pumps, an electric motor fordriving the other pump, means for controllin the electrically drivenwater pump the fuel supply and said electrical device in substantialunison, said means beingbrought into operation by generator conditionsand independent means for automaticallv controlling the liquid from thesteam engine driven pump according to generator conditions.

18. In an apparatus for generating steam, a steam generator, 2. fuelsupply for heating the generator, an igniting device for the fuel, apump for furnishing water to the generator, and means governed bygenerator conditions for automatically controlling in substantialunison-the operation of said igniting device, said pump V'and'the fuelsupply.

19. In an apparatus for generating steam,

a steam generator, a fuel supply for heating the generator, an ignitingdevice for the fuel, a pump for furnishing water to the generator, andmeans rendered operative by the rise or fall in steam pressure in thegenerator above or below a prescribed range for automaticallycontrolling the operation of said igniting device, said water pump andthe fuel supply in substantial unison.

20. In an apparatus for generating steam, a steam generator, anelectrically controlled fuel supply for heating the generator, anelectrical igniting device for the fuel, an electrically driven pump forfurnishing water to the generator, an electrical circuit including theelectrical driving means, the fuel supply control and the ignitingdevice, and means governed by generator conditions for opening andclosing said circuit whereby to automatically control said pump, fuelsupply and igniting device.

21. In an apparatus for generating steam, a steam generator, a fuelsupply for heating the generator, an electrical device for igniting thefuel mixture, a liquid supply for the generator comp-rising two waterpumps and their connections to a source of liquid, a steam engine 'fordriving one of said pumps, an electric motor for driving the other pump,means rendered operative by the rise or fall in steam pressure in thegenerator above or below a prescribed range for controlling the supplyof fuel, said electrical device and the supply of liquid from theelectrically driven pump, and means rendered operative by the rise orfall in the temperature of the fluid in the generator above or below aprescribed range for controlling the supply of the liquid to thegenerator from the steam engine driven pump.

22. In an apparatus for generating steam, a steam generator, means i forsupplying liquid to the enerator, means for supplying fuel for heatingthe generator, an electrical device for igniting the fuel mixture, meansgoverned by generator conditions for automatically controlling theelectrical device and the fuel and liquid supplies in substantialunison, and means or automatically adding an additional supply of liquidto the enerator in accordance with generator con itions. I

23. In an apparatus for generating steam,

a steam generator, means for supplying liquid to the nerator, means forsuppl fuel for heating the generator, an igniting,

tive by the rise or fallin temperature of the fluid in the generatorabove or below a prescribed range for automatically controlling saidadditional liquid supply to the generator.

24. In an apparatus for generating steam, a steam generator, means forsupplying a liquid thereto, an electrical device for controlling saidsupply of liquid, means for supplying fuel for heating the generator, an

electrical device for controlling said supply of fuel,'an electricaldevice for igniting the fuel, and means rendered operative by a fall insteam pressure in the generator below a given amount for bringing saiddevices into operation.

25. In an apparatus for generatin steam, a steam generator, means forsupp ying a liquid thereto, an electrical device for controlling saidsupply of liquid, means for supplying fuel for heating the generator, anelectrical device for controlling the supply of fuel, an electricaldevice for igniting the fuel, means renderedoperative by a fall in thesteam pressure in the generator below a given amount for bringing saiddevices into operation in substantial unison, an additional liquidsupply for the generator, an electrical device for controlling saidadditional liquid supply, and means rendered operative by a riseintemperature of the liquid in the generator above a given degree forbringing said additional liquidsupply controlling device into operation.

26. In an apparatus for generatin steam, a steam generator, comprising ap of pipe coils connected in series, means for supplying liquid to thegenerator, means for supplying a fuel mixture for heating the generator,an electrical device for igniting the fuel mixture, and single meansgoverned by generator conditions for automatically controlling insubstantial unison said electrical device, the supply of liquid to thegenerator and the supply of fuel for heating the generator.- v

27. In an apparatus for generating steam, a steam generator of the flashtype, an elecurality trically controlled device for supplying liquid tothe generator, an electrically controlled device for suppl ing fuel forheating the generator, an electrical device for igniting the fuel, andmeans governed by generator conditions for automatically controllin saiddevices.

28. u an apparatus for generating steam, a steam generator of the flashtype, an electrically controlled device for sup-plying liquid to thegenerator, an electrically controlled device for supplying fuel forheating the generator, an electrical device for igniting the fuel, meansgoverned by generator conditions for automatically controlling saiddevices in substantial unison, and independent means for automaticallychang: ing the relation between the supplies of liquid and fuel.

29. In an apparatus for generating steam, a steam generator, means forsupplying liquid to the generator, means for supplying fuel for heatingthe generator, an electrically controlled device for igniting said fuel,and means for initiating the functions of the liquid and fuel supplymeans and the device for igniting the fuel from a single source ofcontrol.

30. In an apparatus for generating steam, a steam generator, anelectrically controlled device for supplying liquid to the generator,

an electrically controlled device for sup-plying fuel for heating thegenerator, an electrically controlled device for igniting said fuel, andmeans governed by generator conditions for automatically opening andclosing the electrical circuit to said igniting device, the device forsupplying liquid to the generator and the device for supplying fuel forheating the generator.

In witness whereof I have hereunto set my hand this 5th day of February,1918.

LEWIS L. SCOTT. -Witnesses:

. MELBA S. STUMZPF,

GAIL MAoUmE.

